Elevated cardiac vagal tone in hypoestrogenic active premenopausal women with functional hypothalamic amenorrhe

Beverley L. Morris (7240055)

Emma ODonnell (1384770)

Jack M. Goodman (5516660)

John S. Floras (7239164)

Paula J. Harvey (7238525)

The FASEB Journal

English

Loughborough University Institutional Repository

Elevated Cardiac Vagal Tone in Hypoestrogenic Active Premenopausal Women with Functional Hypothalamic Amenorrhea   Emma O’Donnell1, Jack M Goodman1,2, Beverly L Morris3, John S Floras2,3,  and Paula J Harvey4  1Cardiovascular Research Laboratory, Department of Exercise Sciences, University of Toronto, Toronto, Ontario, Canada, and Division of Cardiology at the 2Mount Sinai Hospital, 3Toronto General Hospital, and 4Women’s College Hospital, University of Toronto, Ontario, Canada.   Compared with eumenorrheic women, exercise-trained women with functional hypothalamic amenorrhea (ExFHA) have a low heart rate (HR), absent reflex activation of their renin-angiotensin-system, and augmentation of the normal increase in muscle sympathetic nerve burst incidence during orthostatic stress, suggesting concurrently altered autonomic HR modulation.  To test this hypothesis, three age-matched (pooled mean, 24±1 years; mean±SEM) groups of women were studied: ExFHA (n=11), exercise-trained and eumenorrheic (ExOv; n=17), and sedentary and eumenorrheic (SedOv; n=17). Blood pressure (BP), HR, and HR variability (HRV) in the frequency domain were measured at supine rest and during simulated orthostatic stress induced by graded lower body negative pressure (LBNP; -10, -20, and -40mmHg). Very low (VLF), low (LF) and high (HF) frequency power spectra (ms2) were determined, and due to skewness, were log10 transformed.  LF/HF ratio and Total power (VLF+LF+HF) were calculated.  At baseline, HR and systolic BP were lower (p<0.05), and HF and Total power higher (p<0.05) in ExFHA than eumenorrheic women.  In all groups, LBNP decreased (p<0.05) systolic BP, HF and Total power, and increased (p<0.05) HR, and LF/HF ratio.  However, in ExFHA, HF and Total power remained higher (p<0.05), and HR, systolic BP and LF/HF ratio lower (p<0.05) than in eumenorrheic women, in whom measures did not differ (p>0.05). In conclusion, ExFHA women demonstrate augmented vagal HR modulation, whereas sympathetic HR modulation is unchanged, both at rest and during orthostatic stress.  Less central angiotensin II may play a role.  Abstract Sponsor: Dr. John S Floras Sponsor email: jfloras@mtsinai.on.ca Sponsor telephone number: 416-586-8704  

Elevated cardiac vagal tone in hypoestrogenic active premenopausal women with functional hypothalamic amenorrhea

https://repository.lboro.ac.uk/articles/Elevated_cardiac_vagal_tone_in_hypoestrogenic_active_premenopausal_women_with_functional_hypothalamic_amenorrhea/9620213/files/17267936.pdf

Elevated cardiac vagal tone in hypoestrogenic active premenopausal women with functional hypothalamic amenorrhea

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Loughborough University Institutional Repository